Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Job Classification

In most duration tables, five job classifications are displayed. These job classifications are based on the amount of physical effort required to perform the work. The classifications correspond to the Strength Factor classifications described in the United States Department of Labor's Dictionary of Occupational Titles. The following definitions are quoted directly from that publication.

Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Comorbid Conditions

Factors Influencing Duration

Duration will depend on whether synovitis is acute or chronic, any underlying cause of inflammation, the number of joints involved, whether a joint of the upper limb on the dominant side is involved, job requirements, and response to treatment.

Overview

&COPY; Reed Group

Synovitis is a condition that develops when a joint lining (synovial membrane) becomes irritated and inflamed. Each synovial joint (diarthrosis) is enclosed in a capsule lined with membrane tissue known as the synovium or synovial membrane. The synovium secretes a lubricating fluid (synovial fluid) and is able to adapt to different motions of a joint by stretching, rolling, and folding. When the synovium becomes irritated, it increases fluid production, resulting in warmth, tenderness, and swelling in and around the joint.

A rare, slow-growing, benign tumor of the synovial membranes (pigmented villonodular synovitis [PVNS]) can cause pain and swelling in the knee synovium in 80% of cases and to a lesser extent may involve hip, ankle, or shoulder joints (McGrath).

Synovitis is commonly confirmed with arthroscopic examination. Temporomandibular (TM) joints, which are found where the lower jaw joins the skull, are unusual locations.

Incidence and Prevalence: Synovitis is not sex-specific, although rheumatoid arthritis, for which persistent inflammatory synovitis is a characteristic feature, is 3 times more common in women than in men (Venkateshan). Prevalence of rheumatoid arthritis is 0.8% of the population (Venkateshan).

Joint infection (septic arthritis) is observed primarily in individuals under age 15 and over age 55, and is most common in men (Marquez). Incidence of septic arthritis is 6 to 10 cases per 100,000 population. Following joint replacement surgery, incidence increases to 30 to 70 per 100,000 (Marquez).

Causation and Known Risk Factors

Although the concept that individuals who are exposed to prolonged, repetitive motions of the hand, wrist, elbow, and shoulder, such as those who perform assembly line or keyboarding work or those who participate in throwing sports are at increased risk for synovitis, the science does not confirm this belief. Synovitis can also affect joints of the lower extremities but, again, the incidence rate is not significantly higher in individuals performing repetitive movements of the hip, knee, foot, and ankle during activities such as running, climbing, and jumping than in those who are sedentary.

Synovitis has many causes, including infection (e.g., septic arthritis, tuberculosis), direct joint trauma, allergic reaction, gout, and systemic autoimmune inflammatory diseases (e.g., rheumatoid arthritis). Synovitis can occur as an acute episode limited to one joint, or it can involve multiple joints and be a chronic symptom of a general disease process.

Uric acid overproduction, as seen in gout, places individuals at an increased risk for synovitis. People at risk of uric acid overproduction include those with a history of leukemia, lymphoma, psoriasis, and those receiving chemotherapy. Alcohol consumption, chronic renal failure, and hypertension can lead to a decreased excretion of uric acid, which in turn can lead to uric acid accumulation and an increased risk of gout and associated synovitis.

Recurrent bleeding into a joint space (hemarthrosis) in large joints (mainly knee, ankle, and elbow joints) in individuals with severe hemophilia is a cause of chronic synovitis and arthropathy (blood-induced joint disease [BIJD]).

Diagnosis

History: Although synovitis is typically not activity-related, the individual may describe extended periods of performing repetitive movements or a history of receiving physical forces sufficient to strain the involved joint(s). A medical history of infection, allergic reaction, or inflammatory disease should be investigated, as this may provide clues to underlying conditions causing the synovitis. One joint or several may be involved. Individuals will complain of joint pain, swelling, warmth, and stiffness and may experience relief of symptoms with the use of heat or cold therapy.

Physical exam: Passive and active range of motion is observed for indications of pain, stiffness, and/or joint noise (crepitus). Muscles surrounding the joint are tested for weakness and pain to resistance. Joint-play movements are evaluated for mobility and irritability; they are typically limited and painful. However, if the synovitis is the result of a traumatic joint injury, joint-play may be excessive. Joints will appear swollen, red, and warm to touch, and may have a "boggy" feel to gentle probing with the fingers (palpation).

Tests: Laboratory tests include complete blood count (CBC), urinalysis, and erythrocyte sedimentation rate (ESR), and or C-reactive protein to measure inflammation. If appropriate, a rheumatoid panel and/or joint fluid analysis (following joint aspiration) with Gram stain may be done. Routine x-rays may be indicated to evaluate the joint surface for erosion of the articular surface. Nuclear medicine scans also may provide valuable information, especially during earlier stages of inflammation.

Treatment

Synovitis is most often treated with nonsteroidal anti-inflammatory drugs (NSAID), cold or heat therapy, corticosteroid injections, and rest from aggravating activity. Splinting for part of the day or night to immobilize and support the joint may be needed. Once symptoms are stabilized, exercising the joint(s) is initiated to improve range of motion and restore strength to surrounding muscles.

In destructive synovitis, as found in conditions such as rheumatoid arthritis, surgical removal of the synovium may be required (synovectomy). Destruction of the synovium also can be accomplished with laser therapy/surgery and injections of selectively destructive chemicals (chemical ablation).

Prognosis

Acute, isolated episodes of synovitis usually respond well to conservative treatment. If the affected joint is rested properly, synovitis can improve within a few days but may take up to 8 weeks to fully resolve (Ryan). In chronic synovitis, the course of the underlying disease will determine the outcome. Synovitis can recur if the synovium regrows after synovectomy or chemical or laser ablation of the inflamed synovium if the underlying disease process causes inflammation of the synovium to recur.

Rehabilitation

The goal of rehabilitation for synovitis is to decrease inflammation and pain at the affected joint(s) and then to restore range of motion and strength to the joint(s). Early in the course of synovitis, the physical therapist may instruct the individual to elevate the affected joint to help reduce swelling. The therapist also will educate the individual on how to avoid pressure on the inflamed synovial tissues by applying an elastic bandage, sling, or soft foam pad to protect the involved area until the swelling decreases.

There are several possible treatments to control inflammation resulting from synovitis. At the initial flare-up, the physical therapist may use cold modalities (e.g., ice packs) to control swelling and pain for as long as the joint area is warm to the touch. Electrostimulation combined with a cold treatment may be used to reduce muscle spasms around the inflamed joint and help to decrease pain and inflammation.

When pain and inflammation of the acute stage of synovitis have lessened, heat modalities such as moist heat packs may be used to help relieve joint pain and stiffness and to increase blood flow to the synovium to promote healing. Ultrasound, a treatment that uses high frequency sound waves to produce circulatory changes in the soft tissues or heat that penetrates deep into the involved synovial membrane and surrounding joint, may also be used. Iontophoresis, which uses a small electric current to drive anti-inflammatory medication into the inflamed tissues, may be performed.

Once pain and swelling have been greatly reduced, the physical therapist will perform passive stretching exercises to help restore full range motion to an affected joint. Exercise will be progressed to active stretching and strengthening as appropriate to restore function without recurrence of pain. Modifications may be made by the physical therapist depending on the location of the affected joint, the stage of the inflammation (i.e., acute flare-up or chronic pain), and whether surgery was required. However, this condition rarely requires surgical intervention.

Complications

Ability to Work (Return to Work Considerations)

Limited work (loading) of an affected joint may be a restriction that could require temporary reassignment to a job that puts less stress on the joint. Temporary use of adaptive equipment or assistive devices may be needed. Periods of rest and time off for physical therapy appointments may be necessary. Company policy on medication usage should be reviewed to determine if pain medication use is compatible with job safety and function.

Risk: The risk for recurrence is dependent on the original condition that caused the synovitis.

Capacity: Functional ability will be influenced by the joint or joints involved, the underlying disease, and the requirements of the job.

Tolerance: Large joints with synovitis are usually more painful than small joints. The level of pain will vary by individual's tolerance, the joints involved, and the underlying disease.

Accommodations: Synovitis rarely will require time off work. If the condition persists and synovectomy is performed, employers able to provide accommodations can usually expect early return to work after synovectomy.

Maximum Medical Improvement

Failure to Recover

If an individual fails to recover within the expected maximum duration period, the reader may wish to consider the following questions to better understand the specifics of an individual's medical case.

Regarding diagnosis:

Did the individual present with pain, swelling, and redness of one or more joints?

Was range of motion restricted or painful? Was strength normal?

Were diagnostic x-rays and blood tests done to confirm the diagnosis?

Has cause of synovitis been identified?

Is more than one joint involved?

Would individual benefit from evaluation by a specialist (rheumatologist, sports medicine specialist)?

Regarding treatment:

Is the underlying cause being treated?

Has enough time passed for conservative measures to be effective?

Was physical therapy necessary?

Is individual compliant with recommendations to rest joint or participate in physical therapy?

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